Process for the treatment of petroleum-oils



E. B. COBB.

PROCESS FR THE TREATMENT 0F PETROLEUM OILS.

Arrucmou mm Auczz. Isn.

1,3 1 5 ,623. Patented Sept 9, 1919.

INYEIITOR WITNESS:

UNITED STATES PATENT OFFICE.

ERNEST B. COBB, 0F JERSEY CITY, NEW JERSEY, ASSIGNOR TO STANDARD OILCOMPANY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Sept. 9, 1919.

Application led August 2, 1917. Serial No. 184,072.

To all whom t may concern:

Bc it known that I, ERNEST B. COBB, a citizen of the United States,residing at Jersey City, in the county of Hudson and State of NewJersey, have `invented certain new and useful Improvements in Processes.for the Treatment of Petroleum-Oils, of which the following is aspecification.

My invention relates to new and useful improvements in processes for thetreatment of petroleum oils, and particularly contemplates a process forpurifying and decolori'/,ing petroleum oils which have been subjected totreatment with sulfuric acid, for the purpose of removing from such oilsreaction products such as sulfo-acids resulting from such acidtreatment.

It is well known that petroleum oils have been treated with commercialsulfuric acid, c., of GGD Baume strength for the purposes ofpurification, and afterward either alkalinizing or neutralizing the oilso treated-with soda or other suitable neutralizer, for the purpose ofremoving the acid and reaction products. This treatment, however, is notsatisfactory where extreme degrees of purity are desired, because thefinished oil contained sulfo-acids which could not be 4removed by thewell-known methods of treating with alkali.

My invention particularly contemplates i a process which willcffectually remove practically all of the sulfo-acid products whichremain after the sulfuric acid and alkali treatment, and, therefore,make my improved process available fo-r producing oils which may beeffectually treated to produce a product which is practically colorlessand void of odor.

The invention consists in the improved process to be more fullydescribed hereinafter and the novelty of which will be particularlypointed out and distinctly claimed.

In order that the various steps of the process will be readilyunderstood by those skilled in the art, I have illustrated in theaccompanying drawings one form of apparatus which may be employed withadvantage to perform the process.

Before describing in detail the preferred method of carrying out theprocess, as regards the ingredients, quantities thereof, temperaturesand steps employed, I would state the process briefly, as follows :lI'take a petroleum oil, such, for instance, as is to be employed for theproduction of an oil of a h1gh degree of purity employed for medicinalpurposes, and treat the same with a proper amount of sulfuric acid forthe purpose of removing the color, and those elements producing odor,employing for this purpose sulfuric acid of high strength-for instance,containing 20% of sulfuric anhydrid (S03) which is lOl-'Z; oleum--thatis, it is an acid not only containing no excess free water but one whichconsists of the mono-hydrate with lthe sulfuric anhydrid in solution,and, therefore, of great strength, far beyond Athat hitherto usuallyemployed in the acid treatment of petroleum oil. Other strengths of acidare not necessarily excluded if the character of the oil and the resultsdesired permit.

This acid treatment may be repeated as often as may be desired in orderto produce the required'degree of purification, the oil beingpermittedt0 cool between applications of the acid in order to prevent rapidevolution of gas-sulfurous acid gas due to the chemical reaction, whichmight result in destruction or alteration of the oils, the character ofwhich it is desired to retain unchanged. After each application of theoil the resulting sludge is drawn off and the su ernatant oil is thensubjected to the succee ing application of the acid if furtherapplication is necessary. When the desired number of applications of theacid have been made, the oil is permitted to stand so that the sludgemay settle, which may requn'e anywhere from ten to forty-eight hours.The sludge is then drawn off and tlie'supernatant oil is transferred .toa clean vessel and alkalinized with soda-ash, sal-soda, or

caustic soda in solution, or any other ingredient suitable in oiltreatment for neutralizing the acids-forexample, potash and ammonia. Theaction of the alkali is to neutralize the free acid and also thesulfoacids resulting from the reaction between the acid and the oil, andin certain types of oils, for instance, those from Texas crude, willneutralize the natural `acids therein. This alkali is added in an amountin excess of that required for neutralization, such as generallycontemplated, and may be from 10 to 40 Baume solution in the case ofcaustic soda, for example. I employ alkali ofv great strength, and alarge quantity thereof in order that the supernatant oil resulting afterthe alkali treatment will be practically emulsion-free, the alkaliacting to render-the oil and the alkali solution as little soluble aspossible in each other, and

therebyeffecting a distinct separation. After the alkali treatment thebottom layer containing the excess alkali, and the neutralized sulfuricacid in solution in the 'bulk of the Water are drawn off, leaving theupper layer of oily containing sulfo-acid salts in solution.

The usual method which would be followed at this point would be to washthe oils with water, but this cannot be done for the purpose of removingthe sulfo-acid salts because the addition of the water'for washing wouldresult in an emulsion being formed between the water and the sulfoacidsalts which are-soluble partly in the water and partly in the oil, whichwould result in some of the sulfo-acid salts still remaining in the oil,and a permanent emulsion which it would be practically impossible toremove.

In order to effectually remove substantially all, if not all, of thesulfo-acid salts I` treat the oillcontaining these acid salts asfollows:

The oil is treated by any suitable or well known step, for instance,blowing with air to remove water therefrom preferably as much aspossible. When the alkali is withdrawn the oil may contain as much as'5% water, and I endeavor to remove as much of this water as possible.The oil is then subjected to glycerin .(C3H5(OII)3) which is y Ithoroughly mixed therewith so as to effectually bring the glycerin incontact with all parts of the body of the oil, which glycerin forms asolution of the sulfo-acid salts, but

will not go into solution with the oil, except to a very small extent,if at all. This glycerin should be as water-free as possible. I haveascertained that commercial glycerin, which is 96% pure, will efectuallyobtain the desired results, but I do not limit myself to glycerin 'ofthis high degree of purity aS strengths as low as 90% have been foundsatisfactory, although strengths as low as 80% will not producesatisfactory results. After the glycerin treatment the treated oil ispermitted to stand until it separates into ,viscosity at a temperatureof 100 La ranas contain glycerin and the sulfo-acid salts in solution inglycerin, while the upper layer will be a hydrocarbon oil free fromsulfo-.

acid salts. This oil may then be washed and filtered, whereupon it willbe inodorous and practically colorless, and in which there will be notendency to emulsify when submitted to the washing process. During thesettling, after the glycerin treatment, the oil may be, and preferablyis, maintained at a Suitable temperature, say about 170 ll., to hastenthe settling process, which might take unnecessarily long, due to theviscous nature of the cold glycerin and the oil.

Having now described generally the process I will set forth in detailone example of performing the same, the same being described in shown inthe accompanying drawing.

` The desired oil which has been previously treated with the sulfuricacid of great strength is flowed through a* pipe 1 into a covered tankor receptacle'Q. y As heretofore stated, the oil may be of any typewhich it is desired to purify, for example, an oil of 400 F. on theSaybolt universal viscosimeter, although I do not confine myself toIsuch an oil, as the process is of value in treatment of any viscous oilin which there is liability to the formation of emulsions when subjectedto acid and alkali, for instance, an oil as low as 75 viscosity. In theprevious treatment of the voil with sulfuric acid, the acidl of theconnection with the apparatus in the oil when it comes 'from the still,as a -matter of economy in the use of acid.l The desired quantity ofsettled oil is run into the tank 2, and an alkali solution consisting ofsoda or sal-soda or other suitable alkaline Substance, as heretoforementioned, but preferably caustic soda, `is run into the tank through aninlet pipe 3, this caustic soda solution being preferably from 10 about10 Baume for purposes of economy, but the stronger the solution used themore certain will be the separation. It will be understood that thestrength of the alkali solution and the quantity thereof employed mustbe such that there will be a clear line of separation between the oiland the bottom layer ,or aqueous layer. In employing a 10 strengthof'caustic soda the volume would be about 20% of the body of oil beingtreated. As soon as a proper separation has taken place, which may takefrom ten to to 40 ABaume. I preferably employ a strength of forty-eighthours, but which will be readily apparent upon examination of the oilsby sampling, the bottom layer containing the neutralized acid, water andthe excess of alkali which has not entered into combination, is drawnoff through a pipe 4 leading from the bottom of the tank and connectedto the pipe 5, the pipe si containing a control valve 6, and the pipe 5having a control valve 7. When the bottom layer has been drawn off', theupper layer of oil containing tracesl of water, which may amount to 5%by volume, and practically all of the sulfoacid salts resulting from thealkali treatment will remain in the tank, and the valves 6 and T arethen closed. In order to remove the remaining traces of water which arein the body of oil, the latter is heated by a steam coil S in the bottomof the tank and controlled by inlet valve and outlet valve 10, to atemperature of 200O F., or there-about, this heating` serving to assistin the removal of water when the oil is subjected to blowing with airadmitted to the interior of the tank by a blow pipe 11, the lower oroutlet end of which tern'iinates adjacent the bottom of the tank so thatthe air will permeate the body of the oil. The top of the tank may bepro vided with an outlet vent 12 for the escape of steam and air. Theheating and blowing is carried on until the escape from the vent pipewill cease to show water or steam, which can be determined by any of thewell known means known by those skilled in the art.

The oil is then ready to be subjected to the glycerin, which is admittedto the interior of the tank 2 by an inlet pipe 13. This glycerin, as`heretofore stated, may be of con'nnercial strength, which is about 90%,the more water-free the glycerin is the better being the resultsobtained, although it may be 90%, as I have demonstrated. The glycerinis admitted to the tank in a quantity of about from to 10% by volume ofthe body of oil being treated. I have found that a quantity inproportion of 8% of glycerin by volumewill efficiently serve thepurpose. The body of oil containing the glycerin is thoroughly agita-tedby any suitable means in order to thoroughly admix the glycerin with theoil and bringit in contact with all parts thereof. i A blast of airthrough the pipe 11, heretofore described, will efficiently produce thedesired agitation. This step of treatment of the oil with the glycerin,accompanied by agitation, might take an hour, but this time is notobligatory because the purpose is to produce a solution of thesulfo-acid salts, and a definite separation, and the time for doingthis, can be.

readily determined by test samples, that is, samples may be taken fromtime to time and the step terminated 'when it is clear that a definiteseparation takes place and the oil is free from sulfo-acid salts. Whenthe treatment with glycerin is completed the body being treated ispermitted to settle, which will result in the formation of two layers,the lower layer containing glycerin, sulfo-acid salts in solution inglycerin, and a comparatively small amount of oil, which may be soluble.in the glycerin ,mixture. This settling process may be accelerated byheating by the steam coil 8, and will take from twenty-four toforty-eight hours, although the time stated is not essential as it maybe readily determined by test when a. proper separation has taken place.The upper layer produced from the settling will be the purified oil,free from sulfoarid salts.

Then the` settling and separation accomplished, the lower layer,heretofore described, is drawn off' from the tank 2, through the pipe.it and a pipe 1l, discharging into a still 15 for treatment for thepurpose of recovering the glycerin for further usc. The pipe 1l iscontrolled by a valve 10. After the lower or bottom layer is drawn olfthe purified'oil remains in the tank 2, and possibly small traces of'glycerin mechanically adhering to the interior of the tank. In order toremove these traces of glycerin the purified oil may be washed byflowing water, say 5% by volume of the oil, into the tank through thepipe 3 and agitat ing by the air blast, after which by sett-ling abottom layer is formed containing the water and all the traces ofglycerin not hitherto removed. This bottom layer may then be flowedthrough the pipes Je and 1liinto the still 15. The valve 16 may then vbeclosed and the valves G and 7 opened,

and the purified oil run out of the tank 2, or a separate outlet for thepurified oil may be provided if desired. This purified oil may befurther treated by washing after withdrawal from the tank 2, and finallyfiltered through any decolorizer which is suitable, for instance,fullers earth or clay, whereupon the oil will be water-white, and in theoase of a medicinal oil, be made satisfactory for use.

The alkali mixture and glycerin which is flowed into the still 15 maythen be heated by a suitable furnace 17, preferably` up to a temperatureof about 4500 F., which will first serve to drive off the water, whichwill flow out of the dome 18 and through the pipe 19 to a coil 20 of acondenser 21, wherein the water will be condensed and flowed into one orthe other of two rceeiving tanks 22, 23, connected respectively by inletpipes 24, 25, with an outlet pipe :2G from the condenser coil, the pipes24@ and 25 being provided with hand valves 27, 28, respectively, andeach of the said tanks 22 and 23 may be provided tain some glycerin,Will 'liovv into the tankV 22, which is the first on the condenser out vlet line. When the Water is driven ofi', glycerin and the sulo-acidsalts will remain in the still, the said salts being non-volatile attemperatureV conditions and pressures at Which glycerin is volatile,preferably under vacuum produced by a vacuum pump 33 connected by a pipe34 to the condenser outlet pipe 26, which resultsV in the glycerin beingdriven oil as a vapor iovving through the pipe 19 to the condenser coil,Where it is condensed, and from Which it emerges by the pipe 26 andpasses to the receptacle 23. The distillation is carried on under vacuumor pressure as loW as possible to prevent decomposition of the glycerin.After the distillation has progressed until a small amount or tracethereof remains in the still,

this remaining amount may be recovered by accelerating the distillationby means of open-steam admitted to the interior of the still through asupply pipe 357 having at its lower end a perforated outlet pipe 36.'lhe steam may be used, if desired, throughout the distillation toaccelerate the distillation. The steam supply pipe 35 is provided Withspaced hand valves 37, 38, between Which is a valved outlet pipe 39,'Which latter may be employed as a Water drain to remove Water 'ofcondensation which might collect' in the steam supply pipe above thevalve 38, so

that this Water Will not be permitted to pass y into thestill. The tanks22 and 23 are connected by outlet connections 40, 41, With a pipe 42leading to a liquid pump 43 having an outlet 4pipe 44 discharging intoan open evaporator pan 45, the latter being heated in anyv suitablemanner, as by closed steam coil 46, the inlet and outlet of 1which arecontrolled by hand valves 47, 48. 'lhe evaporator pan is'provided with avalved outlet 49 for removal, and each oithe connections 40` 41 isprovided respectively With hand valves 50, 51.

After the distillation of the glycerin is completed the sulfo-acid saltsremain in the still 15, from which they may be Withdrawn by an outletpipe 52 controlled by an internal valve plug 53 operable by a valve stem54 and handle 55, said outlet 52 also having an external valve 56. Thecondensed products which have passed over into the tanks 22 and 23 willconsist oi a r mixture of Water and glycerin in the tank 22, and theglycerin of a higher degree of concentration 1n the tank '23. Theproducts in the tanks 22 and 23, or either of them,

may be Withdrawn by the pump 43 and de-l livered into the evaporator pan45,'vvhere, by heating by means of the steam coil 46, the

remesa stituting the bottom layer` alter the glycerin treatment, whichis run into the still, Will be alkaline, and for this reason mightresult in decomposition of some of the glyc erin. ln order to obviate'loss of glycerin, which might result from such decomposition, ll mayadd enough sulfuric acid to the mass in the still to make it neutral,and thereby prevent loss, which is likely to occur Were the stronglyalkali mass alone subjected to the heat of the still.

By the term sullo-acid as employed `herein and in the claims, is meantthose products or acids which result from the action of the sulfuricacid upon certain hydrocarbons or elements of hydrocarbons contained inpetroleum oil. By the term sullo-acid salts as employed herein and inthe claims is meant the neutralization products which result from theaction of alkali on the sulfo-acids.

W hat l claim and desire to secure by Letters Patent of the UnitedStates is:

1- The process of treating petroleum oils containing sulfo-acid salts,Which consists in removing said salts from the oil by subjecting the oilto the action of glycerin.

2. The process of treating petroleumcils containing sullo-acid salts,which consists in removing said salts from the oil by subjecting the oilto the solvent action of glycerin.

3. vThe process of treating petroleum oils containing sulfo-acid salts,which consists in removing said salts from the oil by subje'cting theoil to the solvent action of glyc-- erin accompanied by agitation.

4. The process of treating petroleum oils 'containing sulfo-acid salts,which consists in removing said salts from the oil by subjecting the oilto thesolvent action of glycerin accompanied by agitationand heat. y

5. The process of treating petroleum oils containing sulfo-acid salts,which consists in removing said salts'from the oil by sub-` jecting theoil to the solvent action of glycerin under conditionspprecluding thepresence of a substantial amount ofwater.

6. The process of treating petroleum oils containing sullo-acid salts,which consists in removing said salts from the oil by subjecting the oilto the solvent action of substantially Water-free glycerin.

7. The process xof treating petroleum oils containing sulfo-acid salts,which consists Ain removing said salts from thel oil by subjecting theoil to the solvent action of glycerin of over purity.

8. The processof treating petroleum oils containing sulo-acid salts,which consists in removing said salts from the oil by subjectiug the oilto the solvent action of glycerin of over 00% purity, accompanied byagitation and heat.

0. The process of treating oils which consists in subjecting the oil tothe action of sulfuricl acid and an alkali, and removing the impurities`resulting from the acid and alkali treatment by subjectingl the oil tothe action o'tA glycerin.

10. The process of treating oils, which consists in subjecting the oilto sulfuric acid and alkali of such strength and quan-V tity as toproduce a clear line of separation between the oil and the aqueous layerupon settling, 'separating the oil from said aqueous layer, and removingthe impurities resulting from the acid and alkali treatment bysubjecting the oil to the solvent action of glycerin.

l1. The process of treating oils, which consists in subjecting the oilto sulfuric acid and alkali of such strength and quantity as to producea clear line of separation between the oil and the aqueous layer uponsettling, separating the oil from said aqueous layer, dehydrating theoil and removing the impurities resulting from the acid and alkalitreatment by subjecting the oil to the solvent action of glycerin.

. l2. The process of treating oils, which consists in subject the oil tosulfuric acid and alkali of such strength and quantity as to produce aclear line'of separation between the oil and the aqueous layer uponsettling, separating the oil :trom said aqueous layer, dehydrating theoil and removing the impurities resulting from the acid and alkalitreatment by subjecting the oil to the solvent action of glycerinsubstantially tree from water.

13. The process of treating oils which consists in subjecting the oil tosulfuric acid and alkali of such strength and quantity as to produce aclear line of separation between the oil and the aqueous layer uponsettling, separating the oil from said aqueous layer, dehydrating theoil and removing the impurities resulting from the acid and alkalitreatment by subj ecting the oil to the solvent action of the glycerin,Washing the oil and filtering it. s

14. The process of treating petroleum oils containing sulfo-acid salts,which consists in subjecting the said oil to the solvent action ofglycerin, settling out the glycerin and the solution of sulfo-acid saltsin glycerin, and Washing and ltering the supernatant oil.

15. The process of treating petroleum oils containing sulfo-acid salts,which consists in subjecting the said oil to the solvent actionofglycerin, settling out the glycerin and the solution of sulfo-acidsalts in glycerin and recovering the glycerin.

16. The process of treating petroleum oils containingr salto-acid salts,which consists in subjecting the said oil to the solvent action ofglycerin, settling out the glycerin and the solution of suite-acid saltsin glycerin and recovering the glycerin by distillation and evaporation.

17. The process ot' treating petroleum oils, which consists insubjecting the oil to strong sulfuric acid in proportion ot about 37% byvolume of the oil treated. then treating the oil with alkali of from l0Oto 40C Baumel in amount of about of the body ot oil being treated,thereby producing a clear line of separation between the oil and theaqueous layer upon settling. and removing the impurities resulting fromthe acid and alkali treatment by subjecting oil to the solvent actionot' glycerin.

18. The process of treating petroleum oils, which consists in subjectingthe oil to strong sulfuric acid in proportion of about 37% by volume ofthe oil treated, then treating the oil with alkali of from 10C to 10oBaume in amount of about 20"( of the body of oil being treated, therebyproducing a clear line of separation between the oil and the aqueouslayer upon settling, and removing the impurities resulting from the acidand alkali treatment by subjecting the oil to glycerin in amount from 5%to 10% by volume of the body of oil.

19. The process of treating petroleum oils. which consists in subjectingthe oil to strong suliuric acid in proportion of about 37% b v volume ofthe oil treated, then treating the -oil with alkali of from 10o to 400Baume in amount ot' about 20% of the body of oil being treated, therebyproducing a clear line of separation between the oil and the aqueouslayer upon settling, separating the oil from said aqueous layer,dehydrating the separated oil and removing the impurities resulting fromthe acid and alkali treatment by subjecting the oil to the solventaction of glycerin.

20. The process of treating petroleum oils, which consists in subjectingthe oil to strong sulfuric acid in proportion of about 37 by volume. ot'the oil treated, then treating the oil with alkali of from 10o to 40oBaume in amount ot' about 20% of the body of oil being treated. therebyproducing a clear line ot' separation between the oil and the aqueouslayer upon settling. separating the oil from said aqueous layer.dehydrating the separated oil and removing the impurities result- `ingfrom the acid and alkali treatment by subjecting the oil to thesolvent'action of glycerin. which is practically Water-free and inamount o't` from about 5% to about 10% by volume of the body of oil.

21. Ihe process ot' treating petroleum oils, which consists insubjecting the oil to strong sulfuric acid in proportion of about 37% byLemma Volume of the oil treated, then treating tbe giyoerinnvbieb ispractically Water-free and voil Withealkaii of from 10 to 40 Baume in inamount of about 8% by volume of the amount of about 20% of the body ofoil bebody of oil. ing treated, thereby producing a clear line in'testimony whereof have hereunto 5 of separation between the oil and theaqueous Signed my name in the px'esenee of tWo subl5 layer uponsettling, separating the oil from sciibing Witnesses.

said aqueous layer, dehydrating the sepa- ERNEST B. @@BB. rated oii andremoving the impuities resuit- Witnesses: ing from the acid and alkalitreatment by ROBERT Boxen,

10 subjecting the oil to the solvent action of THoMAs MITQHELL.

